Mainsheet rigging alternative

[NoExit]

I'm seeking your insights, troubleshooting and better ideas for an alternative mainsheet rigging. I have two aims here:

1. Control the mainsheet from the helm, especially when single-handed, as well as from the current location at the winch on the cabin top.
2. Add purchase, so I can control and main by hand in most conditions, without needing the winch.

Current mainsheet rigging (below): Controlled at the cabintop winch only, runs along the cabintop through a clutch and an organizer to the mast base, where it turns up and then into the boom, exiting near the boom end, turning down on a block to the traveller and then back up to a boom bale at the end of the boom where it's tied off.

Option #1 (below): In which it exists the boom, through a turning block down to the smaller sheave on a fiddle block on the traveller, back up to the boom, around a turning block and back down to the larger sheave on the fiddle block with a cam on the traveller, where I can control it from the helm.

Option #2 (below): In which it exists the boom and turns through the larger sheave of a fiddle block on the boom, down to the smaller sheave on a fiddle block on the traveller, back up to the smaller sheave on the fiddle block on the boom, and down again to the larger sheave on the fiddle block with a cam on the traveller, where I can control it from the helm.

What do you think? Please let me know.

 

[heritage]

Why not eliminate the line running up the mast and through the boom altogether.
BTW, that is one of the best posts I have seen explaining and illustrating a complicated subject.

 

[NoExit]

Why not eliminate the line running up the mast and through the boom altogether.
BTW, that is one of the best posts I have seen explaining and illustrating a complicated subject.

It’s a great question. Only tall people like me (6’4”) will be able to control the main from the traveller high above the helm with this mod, so I want to keep the option for non-freaks to be able to help when I have able crew. Also, in high winds, I suspect I'll still need a winch to bring the main in.

 

[garymalmgren]

RE: Current mainsheet rigging (below): Controlled at the cabintop winch only

How much effort do you need to put into winching to control the main in heavy weather?

The reason that I ask is that that is how much effort you will need with your modified system with NO winch.
It could be hard work!

Gary

 

[NoExit]

RE: Current mainsheet rigging (below): Controlled at the cabintop winch only

How much effort do you need to put into winching to control the main in heavy weather?

The reason that I ask is that that is how much effort you will need with your modified system with NO winch.
It could be hard work!

Gary

In the current configuration, I need the winch in all but the lightest winds. I'm not sure it's even 2:1 now. One aim with a new configuration is to add enough purchase to avoid winching in all but the heaviest winds. Both these options look to me like 3:1 or maybe 4:1 purchase (I'm no expert, so if anyone knows for sure, please let me know), but I figure friction will reduce that more in Option 1 and Option 2 with the angles (though in reality they're not as extreme as in the not-to-scale diagram).

 

[PaulK]

Your two-ended sheet might work well, but you will likely need more mechanical advantage at the aft end. On our J/36 we had enough purchase to handle a 350 square foot mainsail at the aft end of the boom without a winch. It was done by having a doubled sheet, so that by pulling both lines you had 4:1 mechanical advantage,(moves the sail pretty quickly) but pulling just one gave you 8:1 (fine-tune and plenty of power).

If you can get enough purchase at the traveler end you might not need the winch at all. If the sheet was rigged to hang forward of the arch leading to a swivel cleat mounted on or near the tabernacle, anyone could handle it, including the helms person.

 

[Davidasailor26]

What you have now is basically 2:1. Options 1 and 2 are both 3:1. That’s better, but on a 31’ boat my guess is it would still be inadequate. Also remember with the sheet up above your head you won’t be able to pull as hard as the conveniently mounted cabin top winch. It’s much harder to get leverage up high than chest height.

The other thing you may need to consider is how the fiddle block will work that high up. Usually a fiddle block cam needs to have the line pulled up a bit, or at least straight out, to catch. With the block that high I’d worry about having the sheet pop out of the cam when it’s pulled on, potentially dumping the sail from a beat.

 

[jssailem]

It’s your boat, so what I say is only an opinion.

The loose ends at both ends opens up a risk that both ends are loose at the same time and you will loose control of your mainsail.

The only time blocks provide mechanical advantage is when the line between the sheave supports the load. I see a 3:1 system. If the clutch let’s go the line runs loose. The sheaves on the line running through the boom down the mast and back to the cockpit are turning blocks. They provide no mechanical advantage.

Use a two sheave becket block with a cam cleat that secures to a pedestal in the cockpit near the helm. Attach a two sheave block on the end of the boom. Located in front of the helm will make the 4:1 mechanical advantage available to captain and crew. Should be adequate for all crew to control the Mainsheet on your 31ft boat manually in all breezes with out the winch.

 

[NoExit]

Thanks everyone. I'll take some of these ideas back to the sketchpad and mess around a bit. It may be possible after all to eliminate the cabintop/in-boom portion and just go straight from the boom end to the traveler with fiddle, double or even triple blocks, and then down to the pedestal to cleat.

 

[jssailem]

The original set up for the Hunter 31 was a mid-boom Mainsheet rig with what looks to be a 5:1 or 6:1 setup

This is to control a 205sqft sail. They needed the mechanical advantage with the winch because it is a mid-boom rig. Note the design has the rig blocks spread on the boom so as not to break the boom. When you move the Mainsheet rig to the end of the boom the sail control forces are less. 3:1 or 4:1 works there.

I understand your desire to control the Mainsheet whil at the helm solo sailing. You have a couple of possibilities all of which are a compromise.

• The pedestal on the deck in front of the helm will work. It may make the cockpit feel more crowded. It may get in the way of relaxing in the cockpit after sailing.
• You could learn to stear the boat from in front of the helm where yocan better handle the sails.

Two ideas there are likely many more. Compromise is what makes sailing a sport with mental challenges.

 

[NoExit]

The original set up for the Hunter 31 was a mid-boom Mainsheet rig with what looks to be a 5:1 or 6:1 setup
View attachment 232099
This is to control a 205sqft sail. They needed the mechanical advantage with the winch because it is a mid-boom rig. Note the design has the rig blocks spread on the boom so as not to break the boom. When you move the Mainsheet rig to the end of the boom the sail control forces are less. 3:1 or 4:1 works there.

Many thanks. I'm going to aim for 4:1 minimum.

 

[Will Gilmore]

two aims here:

1. Control the mainsheet from the helm, especially when single-handed, as well as from the current location at the winch on the cabin top.
2. Add purchase, so I can control and main by hand in most conditions, without needing the winch.

Why do you want to maintain the current cabintop control?

With your sheet blocks and traveler on the arch, you could skip the boom-to-mast run and lead the sheet down one leg of the arch to the transom. That way you could control the sheet from the helm. Perhaps you even have room to mount a winch there?

-Will

 

[thinwater]

a. Now you will have a rope whipping about overhead during jibes. You need to work that out, or it will snag on things like the wheel or your neck.

b. A good autopilot is vital to single handing. That makes going forward pretty easy. But jibes pretty much need to be done with the auto-tack feature (which works better anyway).

c. Your leverage on the beam cam cleat is going to be terrible. Very hard to cleat if there is any wind at all.

Interesting. I would beg or borrow some blocks and test it on a light air day before digging in. My guess is that you will discard the idea. It's too bad; so many boats move lines away from the helm to make the cockpit seem more open at boat shows. This is the crazy result. Before I buy a boat, I always picture myself at the helm singlehanding. If I can't handle it from there, it fails. No other features will overrule that.

 

[NoExit]

a. Now you will have a rope whipping about overhead during jibes. You need to work that out, or it will snag on things like the wheel or your neck.

b. A good autopilot is vital to single handing. That makes going forward pretty easy. But jibes pretty much need to be done with the auto-tack feature (which works better anyway).

c. Your leverage on the beam cam cleat is going to be terrible. Very hard to cleat if there is any wind at all.

Interesting. I would beg or borrow some blocks and test it on a light air day before digging in. My guess is that you will discard the idea. It's too bad; so many boats move lines away from the helm to make the cockpit seem more open at boat shows. This is the crazy result. Before I buy a boat, I always picture myself at the helm singlehanding. If I can't handle it from there, it fails. No other features will overrule that.

I appreciate the insights from a seasoned single-hander. I'll definitely test different set-ups with borrowed parts before I invest in a quality mainsheet system for the final choice.

 

[NoExit]

Why do you want to maintain the current cabintop control?

With your sheet blocks and traveler on the arch, you could skip the boom-to-mast run and lead the sheet down one leg of the arch to the transom. That way you could control the sheet from the helm. Perhaps you even have room to mount a winch there?

-Will

Interesting idea. I'll take a look at how that might work.

 

[thinwater]

To get a feel for the forces involved, try trimming with the current set-up without using a handle in the winch. I double you can get the main in above about 5-6 knots. My F-24 uses a 7:1 mainsheet, and I really set my feet in a blow. Hobie 16s (300 pounds) use 6:1 or more. I had 4:1 plus winch on my PDQ 32, and I could only hand trim in very light conditions, that with good waist-level leverage. Also, remember that the sheet cannot be released from cam cleats unless you can pull it in, at least most of the way, first. It jams.

 

[Project_Mayhem]

I've seen a few boats that had a double set of blocks and one very long line line. Both ends of the line are made to be pulled on. Grab one end for higher purchase and two for higher speed. I'm sure there's a name for this setup and would love to know what it is

 

[jssailem]

@Project_Mayhem I think you are talking about this.

https://www.harken.com/en/support/selection-tools/system-diagrams/mainsheet-2-speed-systems/

 

[Project_Mayhem]

@Project_Mayhem I think you are talking about this.

https://www.harken.com/en/support/selection-tools/system-diagrams/mainsheet-2-speed-systems/

Yep, same configuration

 

[PaulK]

Yep, same configuration

Like I said - works on a J/36.